(2001; 179 pages)
Acute enteric infections
Typhoid and paratyphoid fever
Typhoid and paratyphoid fever are caused, respectively, by the pathogens Salmonella typhi and S. paratyphi, which are specific to humans. Transmission occurs via contaminated water and/or food. Following treatment with antimicrobials, about 10% of patients relapse and 1 - 3% become chronic carriers of infection.
Chloramphenicol 1g (children 25mg/kg; maximum 750mg) orally every 6 hours for 10 - 14 days
ciprofloxacin 500 - 750mg (children 10 - 15mg/kg; maximum 500 mg) orally every 12 hours for 5 - 14 days (contraindicated during pregnancy)
sulfamethoxazole 800mg + trimethoprim 160mg (children: 20mg/kg + 4mg/kg; maximum 800mg + 160 mg) orally every 12 hours for 3 days.
Ciprofloxacin 500 - 750 mg orally every 12 hours for 4 - 6 weeks (contraindicated during pregnancy; children: ampicillin 10mg/kg (maximum 250mg) i.m. every 6 hours for 4 - 6 weeks).
In many developing countries chloramphenicol is preferred, due to its lower cost. However, the prevalence of resistance to the drug is increasing. Ciprofloxacin is not licensed for either of these indications in children, but is frequently used in short courses. Chloramphenicol and ampicillin appear to be less effective than ciprofloxacin in treating chronic carriers of infection. However, prolonged use of ciprofloxacin in children should be avoided.
Infectious enteritis due to Salmonella spp. other than S. typhi
In infectious enteritis due to Salmonella enteritidis, treatment is the same as that recommended for typhoid fever (see above). In other circumstances antimicrobial therapy is not recommended. However, chronic bacteraemia, metastatic infections or enterocolitis in patients with sickle-cell disease, HIV infection or other predisposing conditions must be treated.
In developing countries multiresistant salmonella infections (including septicaemia) may be nosocomial in origin, especially among children. Recommendations for antimicrobial therapy should be based on data on the susceptibility of local strains.
Enteritis due to enterotoxigenic Escherichia coli
Chemoprophylaxis against so-called "traveller’s diarrhoea" is not indicated. Mild cases require no treatment. However, antimicrobial therapy should be considered if diarrhoea persists or is severe (e.g. more than five bowel movements per day, bloody diarrhoea and/or fever).
Sulfamethoxazole 800mg + trimethoprim 160mg (children: 20mg/kg + 4mg/kg; maximum 800mg + 160mg) orally every 12 hours for 3 days
ciprofloxacin 500 mg (children: 10mg/kg; maximum 500mg) orally every 12 hours for 3 days (contraindicated during pregnancy).
Tetracycline, doxycycline, chloramphenicol and cefalosporins are not recommended. Ciprofloxacin is not licensed for use in children for this indication, but may be used for short courses if there are no suitable alternatives.
Intestinal protozoal infections
Amoebiasis is an uncommon form of bloody diarrhoea due to the protozoan Entamoeba histolytica. The diagnosis should be considered if a patient has persistent bloody diarrhoea (dysentery) despite therapy for shigellosis. Only certain strains of E. histolytica are pathogenic and asymptomatic carriers are common in endemic areas. Patients with invasive disease require consecutive treatment with a systemically active amoebicide followed by a luminal amoebicide in order to eliminate any surviving organisms in the colon. Clearance of cysts in the faeces should be mainly considered in patients living in nonendemic areas.
Metronidazole 10mg/kg (maximum 250mg) orally every 8 hours for 8 - 10 days (adults and children; contraindicated during pregnancy)
diloxanide furoate 500mg (children: 6 - 7mg/kg; maximum 500 mg) orally every 8 hours for 10 days.
Giardia lamblia is a flagellated protozoan which is transmitted from person to person mainly via faecal contamination of food or hands. It occurs worldwide, particularly where sanitation is poor, and is a common cause of both acute and persistent diarrhoea among children in developing countries.
Metronidazole 2g (children: 30mg/kg; maximum 1.2g) orally every 24 hours for 3 days (contraindicated during pregnancy)
tinidazole 2g (children: 50mg/kg; maximum 2g) orally in a single dose (contraindicated during pregnancy).
Necrotizing enterocolitis due to Clostridium difficile
This is a form of pseudomembranous enterocolitis caused by toxigenic Clostridium difficile, following alteration of the intestinal microflora. Previous use of antimicrobials, especially ampicillin, cefalosporins and clindamycin, is often implicated. Treatment with any suspect antimicrobial should be ceased immediately. If toxigenic C. difficile is proven or suspected, treatment should be initiated promptly.
Metronidazole 200mg (children: 12.5mg/kg; maximum 200 mg) orally every 8 hours for 7 - 14 days (contraindicated during pregnancy).
Patients who fail to respond to treatment with metronidazole should receive vancomycin 125 mg (children: 5mg/kg; maximum 125mg) orally every 6 hours for 7 - 14 days.